During my week as a robot, I often felt entranced by the experience of seeing and talking through a machine. The illusion of inhabiting a different body is quite powerful.

People who have teleoperated robots for extended periods report that their brains can become intimately connected to the machine. Filmmaker James Cameron, for example, said in a talk this year that while shooting his documentary on the Titanic wreck, he had a revelation. Piloting robotic submersibles into the murky depths, he said, made him realize "you actually can have these robotic avatars, then your consciousness is injected into the vehicle, into this other form of existence." He later took those ideas to the extreme in his 3-D blockbuster Avatar.

Hiroshi Ishiguro is a Japanese roboticist who creates telepresence robots that look like real people [see "The Man Who Made a Copy of Himself," IEEE Spectrum, April 2010]. He's built robot copies of himself, his daughter, and a young woman [photo, left]. Ishiguro claims that while teleoperating his clone he could feel a tingle on his own cheek when someone touched the robot's cheek. If that phenomenon could be amplified, could our brains "forget" about our old bodies and adopt robots as their new vessels?

Philosophers have pondered similar questions for ages. Descartes proposed that our knowledge of the world was always indirect and imperfect and that we couldn't trust our senses. "What do I see from the window," he wrote, "beyond hats and cloaks that might cover automatic machines?" Kant and others refuted that view, arguing that we indeed sense and understand the world directly.

The answer probably lies somewhere in between. We sense the world directly, but our brains interpret the data and create their own versions of reality. That means that our sense of embodiment—or disembodiment—is more malleable than most people think.

Researchers have shown they can induce out-of-body sensations by delivering electrical shocks or electromagnetic waves to the temporal lobes of volunteers. More recently, scientists have used virtual reality to make subjects experience other people's bodies, or even a mannequin's, as their own.

But when it comes to robots, "little is known about how teleoperation affects the operator," says Victoria Groom, a researcher at Stanford's Communication Between Humans and Interactive Media Lab. She says a number of factors affect how "embodied" the operator feels. These factors include the robot's appearance, whether it's partly autonomous, and whether the operator is using a monitor or virtual-reality goggles.

Will robotic telepresence ever come closer to the real thing? And will people then decide to give up their human bodies and become avatars for good, as some characters in Avatar did? It's a prospect that appeals to some and shocks others.

"Even the most gentle person-robot interaction would never be a caress, nor could one use a delicately controlled and touch-sensitive robot arm to give one's kid a hug," Hubert Dreyfus, a philosopher at the University of California, Berkeley, argues in The Robot in the Garden: Telerobotics and Telepistemology in the Age of the Internet, a compendium of essays on telerobotics.